To manufacture 3-dimensional memories, processing layers, including a plurality of sacrificial layers and a plurality of insulation layers, are formed that alternate with each other, and memory holes are formed in the processing layers. Memory elements are formed in the memory holes and the sacrificial layers are subsequently substituted with electrode layers. However, when an aspect ratio of the memory hole increases, an aspect ratio of a hole pattern of a mask layer for processing the processing layer also generally increases. In this case, when the hole pattern is formed, there is a problem that a side surface of the hole pattern is eroded by etching. When the side surface is eroded, there is a possibility that adjacent hole patterns may become connected. The same problem may also occur when openings are formed in various films.